It is already known that certain imidazole derivatives have fungicidal properties (cf. EP-A 0 298 196). Thus, for example, 4-chloro-2-cyano-1-morpholine-N-ylsulphonyl-5-phenylimidazole or 4-chloro-2-cyano-5-phenyl-1-(2-thienylsulphonyl)-imidazole can be employed for controlling fungi. The activity of these substances is good, but in some cases leaves something to be desired at low application rates.